Psilopsida

plural noun

Psi·​lop·​si·​da

sīˈläpsədə

: a subdivision of Tracheophyta comprising vascular plants with no roots, leaves only partially differentiated or lacking, no leaf traces, a usually protostelic vascular cylinder, and the sporangia merely terminal enlargements of the stem compare lycopsida , pteropsida , sphenopsida

Word History

Etymology

New Latin, from psil- + -opsida (as in lycopsida)

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